EP3344891B1 - Brake-caliper guide for a disc brake, guide member for a brake-caliper guide - Google Patents

Description

The invention relates to the field of brake caliper guides for disc brakes, such as. B. for disc brakes of the sliding caliper or floating caliper type. With these disc brakes, the brake caliper moves relative to the axle-mounted brake carrier. Accordingly, guidance in the axial direction is required. Guide bars serve as guiding elements. At the same time, sealing measures must be provided to protect against the ingress of dust and dirt, for which purpose bellows known from the prior art are often used.

When guiding the brake caliper according to the DE 10 2004 003 083 A1 The brake caliper is guided on the axle-fixed brake carrier by means of plain bearings, each consisting of a guide bar attached to the brake carrier and a hole in the brake caliper. The hole is located on a bearing bush that is pressed into a surrounding hole in the brake caliper. To protect the guide against the ingress of dust and dirt, a bellows is used, which is fixed with one end opposite the brake caliper and with its other end opposite the brake carrier. The end section fixed to the brake carrier is designed as a bead that sits in an annular groove in the guide bar. An additional ring is used to secure the bead, which surrounds the guide bar and extends over the bead and thus secures it.

Next is from the EP 2 233 767 A1 a brake caliper guide is known, in which a fastening structure is provided on the inside of the ring, which locks the ring on the annular groove in the longitudinal direction facing away from the bellows. As a result of this longitudinal locking of the ring, the bead-shaped end section of the bellows is still held securely in the groove of the guide bar even if the bellows is strongly compressed, for example during the assembly process.

The object of the invention is to provide a brake caliper guide and a guide bar with which the positioning of a bellows known from the prior art, for example from the JP 59-116645 , and/or the ring on the guide bar can be further and permanently improved.

To solve this problem, a brake caliper guide with the features of claim 1 and a guide bar for a brake caliper guide with the features of claim 7 are proposed.

The guide bar is provided with a depression, offset in the longitudinal direction from the bottom of the annular groove. The fastening structure formed on the ring rests against a wall of this recess. To achieve a positive fit, the wall is a wall facing the annular groove, i.e. directed towards the annular groove. The annular groove, together with the recess, forms a common groove space divided by a step, with the wall extending outwards from the step.

To seal the bead formed on the bellows, it is provided with a sealing lip formed on the bead. In this way, this sealing lip comes into complete contact in the circumferential direction with the step-shaped cross section of the annular groove, whereby a particularly good and permanent seal of the bellows against the guide bar is achieved.

Various embodiments of the invention are specified in the respective subclaims.

With regard to the guide bar of the brake caliper guide, it is proposed that the depression locking the ring in the longitudinal direction is located between the annular groove and the end of the two ends of the guide bar that is closer to the annular groove. This closer end of the guide bar is the one with which the guide bar is attached to the brake carrier of the disc brake.

Preferably, the depression is a groove extending over the circumference of the guide bar, the depth of which is less than the depth of the annular groove in the area of the groove bottom.

The depression can either be formed spatially separate from the annular groove on the guide bar, or the annular groove, together with the depression, forms a common groove space divided by a step, with the wall extending outwards from the step. In this case, the bead of the bellows rests against the step, and the fastening structure of the ring is supported on the wall. Preferably located on the step only the bead of the bellows, and only the fastening structure of the ring is supported on the wall of the depression.

Furthermore, it is proposed that the radial height of the step is between one third and two thirds of the depth of the annular groove in the area of the groove bottom. Furthermore, the groove bottom should have a width in the axial direction which is five to ten times as large as the width of the step extending in the axial direction.

With regard to the bellows, it is proposed with a design not according to the invention that the sealing lip is formed on the bead away from the bellows. The sealing lip increases the overall width of the bead in the longitudinal direction of the bellows. Nevertheless, the additional sealing lip prevents the insertion of the bead into the annular groove from being made more difficult. Because according to an embodiment not according to the invention, the sealing lip is formed on an inner surface of the bead. The sealing lip can also be formed on an end face of the bead facing away from the bellows. Not according to the invention, the sealing lip is supported on the groove bottom of the annular groove, on a recess arranged axially offset from the groove bottom and on a step between the annular groove and the recess. Not according to the invention, the sealing lip can be supported on a fastening structure which is part of a ring surrounding the guide bar, extending beyond the outside of the bead and locking the ring in the longitudinal direction facing away from the bellows. This leads to a particularly tight fit. In addition, the free end of the sealing lip not according to the invention should be directed outwards. When the bead is inserted into the annular groove, the sealing lip is then automatically pressed towards the bead from the beginning of the insertion, so that the bead can be inserted into the annular groove easily and without major resistance.

According to another embodiment of the bellows not according to the invention, a projection and a gap are formed on an end face of the bead facing away from the bellows, which at least partially covers the sealing lip, the sealing lip being designed to be resilient relative to the projection. The elastic sealing lip can therefore spring back towards the projection when the bead is inserted into the annular groove, whereby the sealing lip does not make it more difficult to insert the bead into the annular groove. If the bead is positioned in the annular groove, the sealing lip springs back, whereby it rests against the step-shaped cross section of the annular groove and seals particularly well here. The projection formed on the bead also allows the path of movement of the sealing lip relative to the Bead can be defined in a defined manner.

According to a further embodiment not according to the invention, the bead is provided on its inner surface with at least two recesses running parallel to one another over the inner circumference of the bead. The bead therefore has a cross section similar to a wave on its inner surface. This allows the number of defined contact lines between the bead and the groove bottom to be increased. This increase in the number of defined contact lines increases the sealing effect of the bead towards the guide bar and also improves the fit of the bead in the annular groove of the guide bar.

Fig. 1

in perspektivischer, zum Teil geschnittener Ansicht eine Fahrzeugscheibenbremse in schwimmender Bauart des Bremssattels, wobei die Bremsscheibe und die Bremsbeläge der Scheibenbremse weggelassen sind;

Fig. 2

in gegenüber Fig. 1 vergrößerter Darstellung einen an dem Bremsträger der Scheibenbremse befestigten Führungsholm;

Fig. 2a

eine vergrößerte Darstellung des in Fig. 2 mit Ila bezeichneten Details;

Fig. 2b

eine vergrößerte Darstellung des in Fig. 2 mit Ilb bezeichneten Details;

Fig. 2c

eine ähnliche Darstellung wie in Fig. 2a, b, jedoch mit einer alternativen Ausgestaltung der Dichtlippe des nicht erfindungsgemäßen Faltenbalgs;

Fig. 3

in perspektivischer Wiedergabe einen teilweise geschnittenen und nicht erfindungsgemäßen Faltenbalg, und

Fig. 4

in einer Schnittdarstellung eine weitere Ausführungsform der Bremssattelführung einschließlich des Führungsholms, des nicht erfindungsgemäßen Faltenbalgs und des den Faltenbalg sichernden Rings.

Two exemplary embodiments of the invention are explained below with reference to the drawings. Show in it:

Fig. 1

in a perspective, partially sectioned view of a vehicle disc brake in a floating design of the brake caliper, the brake disc and the brake pads of the disc brake being omitted;

Fig. 2

in opposite Fig. 1 Enlarged view of a guide bar attached to the brake carrier of the disc brake;

Fig. 2a

an enlarged view of the in Fig. 2 details marked Ila;

Fig. 2b

an enlarged view of the in Fig. 2 details marked Ilb;

Fig. 2c

a similar representation as in Fig. 2a, b , but with an alternative design of the sealing lip of the bellows not according to the invention;

Fig. 3

in perspective representation a partially cut bellows not according to the invention, and

Fig. 4

in a sectional view a further embodiment of the brake caliper guide including the guide bar, the bellows not according to the invention and the ring securing the bellows.

In the Fig. 1 The disc brake shown for a vehicle and in particular for a heavy-duty commercial vehicle trailer consists primarily of a brake carrier 1 attached to the vehicle axle and a brake caliper 2 that is floating, ie slidably attached to the brake carrier 1. Other, also important components of the disc brake are not shown, since these are less important in the context of explaining the invention. This applies, for example, to the brake disc that can be rotated about the axis of rotation 3, and to the brake pads of the disc brake arranged in a pad shaft 5.

The brake carrier 1 is a so-called frameless brake carrier. It has a flat design and does not surround or overlap the brake disc. It extends parallel to the brake disc and transversely to the axis of rotation 3 of the brake disc and it can be firmly attached to a chassis part of the vehicle by means of a mouth-like opening 4, for example to an axle body, of which only the center line 3 is designated. At its end, the axle body is provided with the bearing for the vehicle wheel and the brake disc, which therefore both rotate about the axis of rotation coinciding with the center line 3.

The brake carrier 1, facing away from the axle body, is provided with a recess in which the vehicle's interior of the two brake pads sits with little play, so that the braking torques from this brake pad are transferred directly to the brake carrier 1. The outer of the two brake pads, on the other hand, sits in the brake caliper 2, which for this purpose is provided with support surfaces which absorb the braking torque of the outer brake pad.

The braking or braking reaction torques acting on the floating brake caliper 2 must be transferred to the brake carrier 1 fixed to the chassis. For this purpose, the brake caliper 2 is arranged to be movable in the longitudinal direction on the brake carrier 1 via two plain bearings 6. One bearing 6 shown in the drawing is designed as a fixed bearing and the other bearing as a floating bearing. A fixed bearing is usually referred to as a precisely operating axial guide, which guides the brake caliper 2 with as little friction as possible during braking operation in order to move the brake pads against the rotating brake disc.

On the part of the brake carrier 1, an elongated guide bar 10 belongs to the axial guide 6. This is on its brake carrier side, in Fig. 1 The right-hand end 60 is rigidly fastened to the brake carrier 1 by means of a screw 12. The smoothly machined, cylindrical outside 14 of the guide bar 10 forms the first element of the axial guide 6.

On the part of the brake caliper 2, the axial guide 6 includes a bearing bushing 22 inserted into a bore 20 in the brake caliper 2. The cylindrical bore 20 is formed directly in the material of the brake caliper 2. The bearing bush 22 is preferably a permanently lubricated plain bearing bush, the cylindrical inner wall of which forms the second element of the axial guide 6.

In order to prevent dust and dirt from entering the area of this guide, seals are provided at both ends of the guide. Towards the brake carrier 1 A bellows 16 is provided for sealing, the details of which will be explained in more detail below. The other end of the guide, i.e. the end facing away from the brake carrier 1, is sealed by a cap 17 which is attached to an opening in the brake caliper 2 there.

Based on Figures 2 and 3 details of the seal to the brake carrier 1 will be described below.

The bellows 16, which surrounds the guide bar 10 over a part of its length, is sealed at its left end in the drawing, ie the end facing away from the brake carrier 1, with a sealing section 19 there relative to the brake caliper 2. For this purpose, the sealing section 19 sits like this Fig. 1 shows, in a correspondingly designed recess of the brake caliper 2 surrounding the guide bar 10.

The other, i.e. H. the end section 39 of the bellows 16 facing the brake carrier 1 is attached directly to the guide bar 10 near the brake carrier 1. For this purpose, the guide bar 10 is provided with a circumferential annular groove 30 in its otherwise cylindrical outside 14 close to the outside 1a of the brake carrier 1. In the essentially rectangular cross section formed by the annular groove 30 there is a bead 31, which forms the end section of the bellows 16 facing the brake carrier 1. The bead 31 has an approximately rectangular cross-section that remains the same over its circumference, and it is an integral part of the bellows 16, which is made of elastic material and preferably rubber. It is located predominantly in and to a small extent outside the cross-section of the annular groove 30.

The bead 31 has a sealing lip 40 formed on the bead 31, which, as shown Fig. 2 and Fig. 3 can be seen, is formed all around the bead 31. The sealing lip 40 is integrally formed on the bead 31, so that the sealing lip 40 consists of the same elastic material. The sealing lip 40 protrudes at least with its free end in the longitudinal direction of the bellows 16, so that the width of the bead 31 is increased by the sealing lip 40. The foot of the sealing lip 40 is formed on the inner surface 41 of the bead 31 ( Fig. 2a, b ). Starting from this inner surface 41, the sealing lip 40 extends outwards with its free end, extending outwards at a substantially 45° angle to the inner surface 41.

The sealing lip 40 can also be formed on an end face 43 of the bead 31 facing away from the bellows 16 ( Fig. 2c ). Accordingly, the sealing lip 40 is supported on the groove bottom 48 of the annular groove 30, on a recess 50 arranged axially offset from the groove bottom 48 and on a step 51 between the annular groove 30 and the recess 50. In addition, the sealing lip 35 is supported on a fastening structure 35, which is part of a ring 33 surrounding the guide bar 10 and extending beyond the outside of the bead 31 and locks the ring 33 in the longitudinal direction facing away from the bellows 16. Starting from the end face 43, the sealing lip 40 also extends outwards with its free end.

On the end face 43 of the bead 31 facing the brake carrier 1, a projection 44 in the form of a bulge and a gap 45 are formed all around. The projection 44 is formed essentially at the middle of the height of the bead 31, but can also be formed at the end regions of the end face 43 of the bead 31. The sealing lip 40 overlaps the projection 44 or the gap 45 over a portion of the projection 44 or the gap 43. The gap 43 or a free space is formed between the projection 44 and the sealing lip 40, so that the sealing lip 40 forms part of the projection 44 can spring back. The sealing lip 40 is therefore elastically movable in the direction of the projection 44 and thus in the direction of the end face 43.

On the inner surface 41 of the bead 31, two mutually parallel groove-shaped recesses 46 are formed, which extend over the entire circumference of the bellows 16. Due to the recesses 46, the inner surface 41 has a wave shape. Due to the wave shape, the number of defined contact lines 47 of the inner surface 41 of the bead 31 with the groove bottom 48 of the annular groove 30 can be increased, since the bulges 49 formed adjacent to the recesses 46 rest in a linear manner on the groove bottom 48 of the annular groove 30.

In the area of the foot of the sealing lip 40, the inner surface 41 also has a bulge 49, so that a contact line 47 of the inner surface 41 to the groove bottom 48 is also formed in this connection area.

The annular groove 30 has the groove bottom 48 and opposite side walls arranged at right angles to the groove bottom 48. The groove wall further away from the brake carrier 1 extends from the groove base 48 radially outwards to the cylindrical outside of the guide bar 10. This groove wall, like the annular groove 30 itself, has according to Fig. 2a the height T.

The groove wall arranged closer to the brake carrier 1, on the other hand, is divided into two, since a depression 50 with a smaller cross section adjoins the annular groove 30 in the axial direction. The depression 50 forms a common groove space together with the annular groove 30.

This is achieved by having a circumferential step or a circumferential paragraph 51. This results in two wall sections 52 and 53 that are offset from one another in the longitudinal direction. The sealing lip 40 rests on the lower wall section 52 and/or on the edge of the step 51, as shown in particular Fig. 2a and 2 B can be recognized.

At the in Fig. 2 , 2a , 2 B In the design of the groove cross section shown, the step-shaped shoulder 51 has a radial height H, which is only approximately 1/2 of the depth T of the annular groove 30. The width B _A of the shoulder 51 viewed in the longitudinal direction of the guide bar 10 and thus the width of the depression 50 is significantly smaller than the width B _R of the groove bottom 48 of the annular groove 30.

In order to secure the bead 31 supported on the groove bottom 48 in the annular groove 30 and at the same time to seal it against the annular groove 30, an additional ring 33 is present. This exerts pressure on the bead 31 directed inwards, i.e. towards the central axis of the guide bar 10, and thus holds it in the annular groove 30.

The ring 33 is composed in the circumferential direction of three larger circumferential segments and three smaller circumferential segments, with larger and smaller segments alternating. The ring 33 is provided with a circumferential longitudinal section 34, with which the ring 33 extends outside over the bead 31 and is supported on the outside on the bead 31. In this way, the bead 31 is pressed into the annular groove 30 over its entire circumference to achieve a sufficient seal. Since the bead 31 is encompassed over its entire circumference, a good seal of the bellows 16 relative to the guide bar 10 is achieved.

On the other segments, which are significantly shorter in the circumferential direction, the ring 33 is provided on the inside with a fastening structure 35 in the form of a resilient nose. Each of these fastening structures 35 extends radially inwards into the cross section of the recess 50 adjacent to the annular groove 30, and thus locks the ring 33 on the guide bar 10, whereby the ring in the bellows 16 faces away Longitudinal direction is locked relative to the guide bar. In addition, the ring 33 can be supported directly against the brake carrier 1.

The Fig. 2a shows based on the section through one of the smaller circumferential segments that each fastening structure 35 is an inwardly projecting nose of the ring 33, which is supported against the wall 53 of the depression 50 facing the annular groove 30. Due to this locking, the ring 33 cannot move to the right Fig. 2a dodge, regardless of its possible support on the brake carrier 1. The securing of the position of the ring 33 in the longitudinal direction achieved in this way is, as described, particularly advantageous when assembling the brake caliper.

Since the groove space in its entirety has a step-shaped cross-section, with the lower groove wall 52 extending from the groove bottom 48 to the step 51 and the upper wall 53 extending from the step 51 to the cylindrical outside of the guide bar 10, the fastening structure 35 lies of the ring 33 only on this upper wall 53.

The stage 51 achieves a defined separation of the contact of the bead 31, in particular the sealing lip 40 of the bead 31, and the contact of the ring 33, in particular the fastening structure 35 of the ring. This is because the step 51 leads to a division into the lower or inner groove wall 52 and the upper or outer groove wall 53, which is offset in the longitudinal direction, with only the bead 31 of the bellows 16 on the wall 52 and only on the wall 53 the ring 33 is supported in the longitudinal direction. These measures help to further and permanently improve the positioning of the bellows 16 and/or the ring 33 on the guide bar 10.

In Fig. 4 a second embodiment is shown. In this case, the depression 50 is not part of a common groove space with the annular groove 30 receiving the bead 31. Instead, the depression 50 is not only axially offset, but is formed on the guide bar 10 spatially separated from the annular groove 30. For this purpose, the guide bar is provided with a separate second groove 50, which here has the cross section of a rectangular groove. However, the recess can also be a groove 50 with a V-shaped cross section, the wall 53 of which facing the annular groove 30 being arranged perpendicular to the cylindrical outer surface of the guide bar 10 in order to achieve the best possible positive fit, as is also the case Rectangular depression 50 in cross section Fig. 4 the case is.

Between the annular groove 30 and the spatially separated recess 50, the guide bar 10 can have the normal cylindrical diameter of its outer side 14. However, a different, smaller diameter is also conceivable here.

In the embodiment according to Fig. 4 A strict spatial separation of the functional areas is achieved. The bead 31 of the bellows 16 sits in the annular groove 30, and the annular groove 30 also serves exclusively to accommodate this bead. On the other hand, the also groove-shaped depression 50 only serves to provide a wall 53 facing the annular groove 30, on which the fastening structure 35 of the ring 33 can be supported in the longitudinal direction. The depression 50 is located between the annular groove 30 and the end 60 of the two ends of the guide bar 10 that is closer to the annular groove 30.

Reference symbol list

1

Brake carrier

1a

Outside of the brake carrier

2

caliper

3

Rotary axis, centerline axis body

4

opening

5

Lining shaft

6

Plain bearings, axial guidance

10

Guide bar

12

screw

14

Outside

16

Bellows

17

cap

19

sealing section

20

drilling

21

Central axis

22

Bearing bushing

30

Ring groove

31

bead

33

ring

34

Longitudinal section

35

structure

39

End section

40

sealing lip

41

Inner surface

42

inner space

43

face

44

head Start

45

gap

46

recess

47

Contact lines

48

groove bottom

49

Bulging

50

depression, groove

51

step, paragraph

52

wall

53

wall

60

End of the guide bar

H

Height of the paragraph

B.A

Width of paragraph

BR

Width of the ring groove

T

Depth of the ring groove

Claims (15)

1. Brake caliper guide for a disk brake, comprising a sliding bearing (6) which is assembled from a bore and a guide bar (10) which is movable longitudinally therein, comprising a bellows (16) which surrounds the guide bar (10) on a partial length for the purpose of protecting the sliding bearing (6) and is provided with a bead (31) so that it can be fixed to the guide bar (10), which bead is supported on a groove base (48) of an annular groove (30) with which the guide bar (10) is provided, and comprising a ring (33) which surrounds the guide bar (10), extends in the axial direction up to the outer face of the bead (31) and is provided with a fastening structure (35) which locks the ring (33) in the longitudinal direction facing away from the bellows (16), characterized by a depression (50) with which the guide bar (10) is provided axially offset with respect to the groove base (48), the fastening structure (35) resting against a wall (53) of the depression (50), which wall faces the annular groove (30).
2. Brake caliper guide according to claim 1, characterized in that the depression (50) is a groove which extends over the periphery of the guide bar (10), the depth of which groove is smaller than the depth (T) of the annular groove (30) in the region of the groove base (48).
3. Brake caliper guide according to claim 1 or claim 2, characterized in that the depression (50) is designed to be spatially separated from the annular groove (30) on the guide bar (10).
4. Brake caliper guide according to claim 1 or claim 2, characterized in that the annular groove (30) together with the depression (50) forms a common groove space divided by a step (51), the wall (53) extending outwardly from the step (51), and the bead (31) of the bellows (16) resting against the step (51), and the fastening structure (35) of the ring (33) resting against the wall (53).
5. Brake caliper guide according to claim 4, characterized in that the radial height (H) of the step (51) is between 1/3 and 2/3 of the depth (T) of the annular groove (30) in the region of the groove base (48).
6. Brake caliper guide according to claim 4 or claim 5, characterized in that the groove base (48) has a width (BR) in the axial direction, which width is five to ten times as large as the width (BA) of the step (51) which extends in the axial direction.
7. Guide bar (10) for a brake caliper guide of a disk brake, comprising an annular groove (30) formed on the outer surface of the guide bar (10), the groove base (48) of which groove forms a seat for the bead of a bellows surrounding the guide bar, and comprising a depression (50), with which the guide bar (10) is provided axially offset with respect to the groove base (48), the depression (50) being provided with a wall (53) facing the annular groove (30) for contacting a fastening structure (35), characterized in that the annular groove (30) together with the depression (50) forms a common groove space divided by a step (51), the wall (53) extending outwardly from the step (51).
8. Guide bar according to claim 7, characterized in that the depression (50) is located between the annular groove (30) and the closer end (60) of the guide bar (10).
9. Guide bar according to claim 7 or claim 8, characterized in that the depression (50) is a groove which extends over the periphery of the guide bar (10), the depth of which groove is smaller than the depth (T) of the annular groove (30) in the region of the groove base (48).
10. Guide bar according to claims 7, 8 or 9, characterized in that the depression (50) is designed to be spatially separated from the annular groove (30) on the guide bar (10).
11. Guide bar according to claim 7, characterized in that the radial height (H) of the step (51) is between 1/3 and 2/3 of the depth (T) of the annular groove (30) in the region of the groove base (48).
12. Guide bar according to claim 7, characterized in that the groove base (48) has a width (BR) in the axial direction, which width is five to ten times as large as the width (fü) of the step (51) which extends in the axial direction.
13. Guide bar according to claim 7, characterized in that the depression (50) is designed spatially separated from the annular groove (30) on the guide bar (10), and, in the mounted state, the bead (31) of the bellows (16) resting against the step (51) and the fastening structure (35) of the ring (33) resting against the wall (53).
14. Guide bar according to claim 13, characterized in that the depression (50) is located between the annular groove (30) and the closer end (60) of the guide bar (10).
15. Guide bar according to claim 13 or claim 14, characterized in that the depression (50) is a groove which extends over the periphery of the guide bar (10), the depth of which groove is smaller than the depth (T) of the annular groove (30) in the region of the groove base (48).

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